Tube rolling mill



Feb. 2, 1960 F. G. BENGTssoN 2,923,187

TUBE ROLLING MILL Filed March 25, 1955 6 Sheets-Sheet 1 NR. mwmum. NS

Feb. 2, 1960 F. G. BENGTssoN 2,923,187

TUBE ROLLING MILL Filed March 25, 1955 6 Sheets-Sheet 2 QM/KM F. G. BENGTSSON TUBE ROLLNG MILL 6 Sheets-Sheet 3 if lil INVENToR.

6,?? WM L? f. m BY l Feb. 2, 1960 Filed March 25, 1955 Feb. 2, 1960 F. G. BENGTssoN TUBE ROLLING MILL 6 Sheets-Sheet 4 Filed March 25, 1955 ffm.

, INVENTOR.

BY [L:

4M/ff Feb. 2, 1960 F. G BENGTSSON 2,923,187

TUBE ROLLING MILL Filed March 25, 1955 6 Sheets-Sheet 5 j@ .7 72M f5 F. G. BENGTSSON TUBE ROLLING MILL Feb. 2, 1960 6 Sheets-Sheet 6 Filed March 25, 1955 INV NTOR.

A" ,47m/May MM, @www States Myinvention relates to apparatus for cold working of material in the form of tubesl and generally similar shapes. More particularly, the invention is concerned with a rolling mill of the Pilger type, in which reciprocating movement is imparted to a die-carrying member, and to cold working tubes and similar shapes with such rolling mill equipment.

Rolling mills of the so-called Pilger type are especially useful for cold working tubular members in order to reduce the dimensions and thickness of such members. Rolling mills of this type employ a reciprocating die-carrying member and include provisions for feeding the material through the equipment. Such feeding provisions usually include feeding members which intermittently feed and turn the material or work piece once during each reciprocation of the die-carrying member having dies which may be in the form of rolls. When tubes and the like are being rolled, a mandrel is usually xed on a rod and disposed within the tube being worked, so that the area of the tube will be reduced between the rollers and the mandrel. In rolling mills of the so-called Pilger type, the mechanisms for feeding the work pieces have been quite complicated. In addition, the equipment heretofore provided for rolling tubes has been further complicated due to the fact that the mandrel is positioned within the tubes while they are being worked.

The object of my invention is to provide an improved apparatus for cold working material, particularly tubular shapes and the like, which is relatively simple and less complicated than equipment of this type heretofore provided. More particularly, it is an object to provide an improved `apparatus for cold working material which will be reliable and sensitive in operation. I accomplish this by providing a roll-bearing member which rotates continuously about the longitudinal axis of the material while it is being cold worked.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention, reference may be had to the following description taken in connection with the accompanying drawing in which Figs. 1 and 1a, together, form a side view, partly in section, of an apparatus embodying my invention which is operable in accordance with the principles thereof;

Figs. 2 and 2a, together, form a top plan view of the apparatus illustrated in Fig. 1;

Fig. 1b is an enlarged fragmentary sectional view illustrating a part of the apparatus shown in Figs. 1 and 2;

Figs. 3 and 4 are enlarged fragmentary side and plan views, respectively, partly in section, of parts shown in Figs. 1 and 2, to illustrate more clearly details of the die-carrying or roll-bearing member;

Fig. 3a is a sectional view taken at line 3a-3a of Fig. 3

atent Figs. 5 and 6 are transverse sectional views taken at lines 5 5 and 6 6, respectively, of Fig. 2a;

Figs. 7 and 8 are enlarged longitudinal and transverse sectional views, respectively, of parts shown in Figs. 1 and 2, to illustrate moreclearly details of the feed members;

Fig. 7a is a sectional view taken at line 7a7a of Fig. 7; and

Fig. 9 is an enlarged fragmentary sectional view illustrating additional details of Figs. 1 and 2.

In Figs. 1 and 2, I have illustrated apparatus embodying my invention which includes a shaft 11 arranged to be driven by a motor, not shown. Provided on the shaft 11 are two gears 12 and 13 which engage and drive separate connecting rod gears 14 and 15, respectively, which are fixed to a shaft 16. The shafts 11 and 16 are mounted on a frame of the apparatus and are journaled in bearings 17 and 18, and 19 and 20, respectively.

The connecting rod gears 14 and 15 are provided with crankpins 21 and 22, respectively, which are lixedtol the ends of connecting rods 23 and 24, the opposite outer ends of which are supported on pins 25 and 26 on a crosshead 27 which serves as a driving member and to which the reciprocating motion of the crankpins is transmitted. The reciprocating crosshead 27 is provided with slides 28 and 29 which are movable in guides 30 and 31, respectively. The crosshead 27 is connected to a diecarrying or roll-bearing member 32 by a tubular tie rod 33 which is fixed at one end to the roll-bearing member 32 and supported at the opposite end in the crosshead 27 on ball bearings in such manner that the rod 33 is rotatable in the crosshead 27. Since the roll-bearing member 32 is rotatable, the tie rod 33 is arranged to be supported in the crosshead 27 in double-acting thrust bearings (not shown), which may be of any well-known type.

Rotating movement is imparted to the roll-bearing member 32 by the same motor (not shown) which effects reciprocating movement thereof. As best shown in Fig. 1, the shaft 11 is connected by a bevel gear transmission 36 to a shaft 35 extending beneath the tie rod 33. The shaft 35 is arranged to be driven at the same speed as the gears 14 and 15, because the feed members, which will be described presently, are arranged to be also driven by the shaft 35, and will therefore work relative to the reciprocating motion imparted to the roll-bearing member 32.

The die-carrying or roll-bearing member 32 is provided with two laterally projecting guides 37, each of which moves on a rail 38, the rails being spaced apart and forming the sides of a rectangular-shaped frame 39 rotatably supported on a pair of tubular hollow members or center pins 4t) and 41 journaled in bearings 42 and 43, respectively, which are mounted on a stationary frame or support d4 of the apparatus. Each of the bearings 42 and 43 is of a type which serves as a radial bearing and also as a double-acting thrust bearing. The center pin 40 extends through the bearing 42, at the outer end of which a sprocket wheel 45 is fixed, such wheel being driven by an endless chain 47 and a sprocket wheel 46 xed to the shaft 35. The center pin 41 is formed with a-central opening sufficiently large so that tubing which is being cold worked can freely pass therethrough, While the center pin 40 is formed with a central opening sufficiently large to allow the tie rod 33 to pass freely therethrough.

In Figs. 1 and 2, l have diagrammatically shown two feeding chucks 48 and 49, which will be described more fully hereinafter. It will be seen that the feeding chuck 4S is arranged directly in front of and ahead of the bearing 43, and serves to feed tube material into the appaftion on the apparatus.

,with the other mandrel. member or roll-bearing member 32 can be maintained acratus, while the other feeding chuck 49 is arranged bel yond the roll-bearing member 32 where tube material 1s worked, and at the vicinity of the crosshead 27. The feeding chuck 49 serves to feed the end of the lasttube beingworked, after it has moved past the feeding chuck 48, so that the last tube will be transported through the apparatus. v

vA supply station 50 for tube material is arranged above the apparatus in any suitable manner. As best seen in Fig. 2a, two elongated mandrel rods 51 and 52 are arranged in mandrel holders 54 and 55, respectively, each of the rods being flexible and carrying a mandrel 53. .As 'illustrated in Figs. 2a and 6, and described more fully hereinafter, each of the mandrel holders 54 and 55 is .movable in a separate guide on a bridge 56, the guide :being of such length that the mandrel 53 associated therewith can be moved in front of the feeding chuck 48. A I pair of rod'lifters 57 and 58 are pivotally mounted at 57' and 58' and are movable upward and downward to transv .fer tubes from the supply station 50 to a horizontal posi- The mandrels and mandrel rods .can be lifted alternatively towards the supply station 50 in order to be inserted into and take hold of a tube while the apparatus is operating on another tube associated l In this way, the die-carrying tive practically continuously during operation of the .'apparatus.

The mandrel bridge 56 desirably is movable in a direction transverse to the lengthwise direction of the apparatus, so that either one or the other of the mandrel -and mandrel rod units may be positioned along the cen- A bracket 34 is provided on the crosshead 27 for supporting a hollow tube 33a which is disposed within the tie rod 33, and through which cooling liquid is delivered into the latter from the liquid line 59, as; shown in Fig. 9. The tie rod 33 is formed with a double wall providing a space through which liquid flows, and from which the liquid is discharged against the dies or rollers forming a part of the die-carrying member 32.

The cooling liquid is discharged into a part of the frame 44 which forms a reservoir 60 for liquid, and from which the cooling liquid may be returned by a pump (not shown) to the dies or rolls through the supply conduit 59. As best seen in Fig. 1, a cover 61 is provided over a part of the apparatus in order to prevent cooling liquid from being splashed from the reservoir.

Referring to Figs. 3 and 4, it will be seen that the rollbearing member 32 comprises dies which are in the form of circumferentially grooved rolls 62 and 63 rotatable on shafts 64 and 65. The dies or rolls 62 and 63 are formed with conical grooves 66 which, during the reciprocating movement of the rolls, act and bear against the tube or pipe being worked while one of the mandrels S3 is positioned therein. The ends of the shafts 64 and 65 are provided with conical-shaped pins 67 and 68 and threaded portions 69 and 70 projecting beyond the pins. The pins 67 and 68 are arranged somewhat eccentrically with respect to the center lines or axial centers of the shafts 64 and 65, so that it will be possible to change the adjustment of the dies or rolls, after refacing thereof, for instance. As seen in Fig. 4, a cylindrical bearing sleeve 71, which can be lubricated in any Well-known manner,

`is provided betwecni'each shaft 64 and 65 and the roll or die associated therewith.

In order to change the die or roll 62, for example, the nut 72 may be removed from the threaded pin 69, and thereafter the nut 73 and the pin 70 may be withdrawn as a unit together with the shaft 64. With the shaft 64 removed, the roll 62 may be lifted from its seat. As seen in Fig. 4, a spur gear 74 is rigidly fixed to the die or roll 62 for positively driving the latter. Movement of gear 74 is effected by a toothed rack 75 which is xed to the rotatable frame 39, so that positive rotation of the gear 74 is effected simultaneously with rotationof the roll or die 62 around the longitudinal axis of the work piece or tubing being worked.

In a similar manner, the roll or die 63 carries a spur gear 76 which engages a toothed rack 77 that is also xed to the rotatable frame 39. The parts just described are so arranged that the same positive `driving movement is Vimparted to the rolls or dies 62 and 63 about their axes which are normal to the axis about which the frame 39 rotates. As seen in Fig. 4, the spur gear 74 for the roller 62 is at one side thereof and adjacent to the toothed rack 75,- and the spur gear for the roll 63 is at the opposite side thereof and adjacent to the toothed rack 77. As seen in Figs. 3 and 4, the diameters of the pitch circles ofr the gears 74 and 76 are somewhat smaller than the diameters of the rolls or dies 62 and 63, wherefore the rolls 62 and 63 can actand move over the tubing being worked without substantial displacement.

The roll-bearing member 32 is formed with openings 78 and 79 through which the toothed racks 75 and 77 can pass. As seen in Figs. 2, 3 and 4, the roll-bearing member 32 is also provided with the guides 37 which extend outwardly from both sides of the member. As

Vbest shown in Fig. 4, the guides'are formed with adjustable jaws 80 and 81. As explained above and seen in Fig. 2, the guides 37 serve to guide the roll-bearing member 32 in its reciprocatory back-and-forth movement on the frame 39.

In Figs. 5 and 6, I have illustrated details of the mechanism provided for operating the pair of elongated mandrel rods 51 and 52 of the apparatus, such flexible rods, as previously explained, being carried on the bridge 56 which is movable in a direction transverse or per' pendicular to the lengthwise direction of the apparatus. As shown in Fig. 5, the mandrel bridge 56, which is supported on two pairs of rollers 82, is provided with two elevating mechanisms 83 and 84 for moving the rod lfters 57 and 58, to which reference has been made above. The elevating mechanisms 83 and 84 are positioned at the end of the bridge 56 which is nearer or closer to the rollbearing member 32. Each elevating mechanism comprises a cylinder 85 having a movable piston 86 therein, the upper end of each piston having an angle iron 87 pivotally connected thereto in which one of the rod litters 57 and 58 rests. The mandrel bridge 56 is moved back and forth on the rollers S2 with the aid of a lever 90 fixed to a shaft 88 positioned below a frame 89 of the apparatus. The upper end of the lever 90 is provided with a roller arm 91 which moves up and down in a guide 92 when the shaft 88 is being turned in a controlled manner by any suitable mechanism (not shown).

The rear part of the mandrel bridge 56, which is shown in Fig. 6, is provided with spaced apart longitudinally extending guides 93 and 94. Each mandrel holder 54 and 55 is mounted on the bridge 56 by a pair of upright brackets 95 and 96 movable back and forth in the guides 93 and 94, the brackets being formed so that the mandrel rods 51 and 52 can be supported on the holders 54 and 55 and at the same time are free to rotate thereon. The mandrel bridge 56 is provided with two uid operated cylinders 97 adapted to move the mandrel holders 54 and 55 back and forth in the guides 93 and 94. This may be accomplished in any suitable manner (not shown), such as, for example, by operating the Cylinders under seater uid pressure, which actuates pistons therein, thereby imparting movement to piston rods adapted to be connected to the brackets 95 and 96 of the mandrel holders 54 and 55.

When new tubing or work pieces are to be introduced into the apparatus for cold working or rolling thereof, the mandrel rod on which the new tubing is positioned is lowered, whereupon the mandrel rod previously in position for a rolling operation is pulled out of such position and raised or lifted. The mandrel bridge 56 is moved laterally of the apparatus into proper position, and the mandrel rod, having. the fresh length of tubing therein, is inserted into the apparatus for cold working.

The feeding chucks 48 and 49, one of which is shown in Figs. 7 and 8, includes a bottom part 101 fixed to the frame of the apparatus, such frame having a pair of horizontal guides 102 extending lengthwise of the apparatus, and also a pair of vertical slots 103. The bottom part 101 serves as a base upon which is movably supported an upper part 104 which imparts rectilinear feeding motions to the tubing or work pieces. The upper part 104 includes a bottom jaw member 106 to which movement can be imparted by a screw 105, and a top jaw member 107 suspended from a lever arm 110 which is Iangularly movable about a shaft 108 and biased downwardly by a spring 109 under tension. The upper part 104 of each feeding chuck is provided with a circular disc 111 having a slot 112. The cylindrical surface of the disc 111 is formed with teeth which engage a worm 113 xed to a shaft 114 having a suitable handwheel.

By turning the handwheel on shaft 114, the disc 111 can be turned or rotated about its axis so that the slot 112 will assume different inclined positions with respect to the vertical, which may be referred to as a zero position. With the slot 112 in an upright or vertical position, the feeding movement imparted to the tubing or work piece is zero, and the greater the angle of inclination of the slot with respect to the vertical, the greater will be the horizontal feeding movement imparted to the tubing. The upper part 104 of the feeding chuck imparts movement to the tubing through a roller 114a which is movable upward and downward in the slot 112. The roller 114:1 is seated on a fork or yoke of an upright rod 115 to which vertical movement is imparted by a cam 116 xed to a shaft 117 which is driven at the same speed (rpm.) as the shaft 16 which drives the rolls or dies 62 and 63. In this way, the feeding motion imparted to the tubing or work pieces can be adjusted during a period of time when the rolls 62 and 63 are free.

In order that the tubing will be held tightly by the jaw members 106 and 107 during the time when feeding of the tubing is being effected, the shaft 117 is also provided with a cam 118 which, with the -aid of a rod 119, acts to lift the lever arm 110 to actuate the top jaw member 107. As best shown in Fig. 8, the cam 118 is effective to keep the jaw member 107 in its raised position during the greater part of each revolution of the shaft 117. For a small interval of time during each revolution of the shaft 117, the spring 109 will be effective to pull the jaw member 107 downward. During this same interval of time the projection on the cam 116 will be elfective to impart a feeding motion to the tubing in the manner just explained. The cam members 116 and 118 are disposed within a shell 120, in the walls of which the shaft 117 is journaled, such shell having a suitable cover 121.

In view of the foregoing, it will now be understood that the die-carrying member 32 reciprocates back and forth on the rotatable frame 39 which is substantially immovable lengthwise of the axis about which it rotates, and that during such reciprocating movement the frame 39 and die-carrying member 32 mounted thereon rotate about the longitudinal axis of the tubing being cold worked. By turning the handwheel on the shaft 114 of the feeding mechanism 48, the distance the gripping members move the work pieces horizontally can be controlled. Further, such movement of the work pieces is effected by the gripping members when the die-carrying member changes direction during its back-and-forth movement. In addition, provision is made for the die members or rolls 62 and 63 to release theirgrip on the work pieces at the instant o-r moment the latter are being moved forward by the gripping members. The grooves in the rolls or dies 62 and 63 are of suflicient width at their wide ends so that the rolls will be released from the work piece at the same instant the feeding mechanism becomes operable.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that, without departing from the spirit and scope of my invention, modifications may be made and certain features used independently of others, as will be pointed out in the following claims.

What is claimed is:

1. A rolling mill for rolling elongated work pieces comprising means providing a stationary support, rotatable structure, means for mounting said structure on said support for rotation about an axis substantially coinciding with the longitudinal axis of the elongated work piece being rolled, said mounting means being so constructed and arranged that said rotatable structure is substantially immovable lengthwise of the axis about which it rotates, rolls having circumferential grooves for embracing the elongated work piece, a member, means for carrying said rolls on said member, means for mounting said roll-carrying member for movement on said rotatable structure in a path parallel to the axis about 'which said structure rotates, means for reciprocating said roll-carrying member back and forth in said path, and means for continuously rotating said rotatable structure while back and forth movement is being imparted to said roll-carrying member by said reciprocating means.

2. A rolling mill as set forth in claim 1 which includes means for mounting said grooved rolls for rotation on said roll-carrying structure about axes normal to the axis about which said structure rotates, and means actuated by said reciprocating means for positively driving said rolls about their axes.

3. A rolling mill as set forth in claim 1 in which said grooved rolls are so constructed and formed that they are released from the workpiece being rolled at intermittent intervals of time while back and forth movement in said path is being imparted to said roll-carrying member by said reciprocating means, and means for intermittently moving the elongated work piece with respect to said roll-carrying member when said grooved rolls are released from the work piece.

4. A rolling mill as set forth in claim 1 in which said grooved rolls are so constructed and formed that they are released from the work piece being rolled substantially at the end of movement of said roll-carrying member in one direction of its back and forth movement in said path by said reciprocating means, and means for intermittently feeding the work piece with respect to said roll-carrying member in a direction which is opposite to said one direction of the back and forth movement of said member when said grooved rolls are released from the work piece.

5. A rolling mill comprising rolls for embracing only the outer periphery of a metal tube, rotatable structure for carrying said rolls, means for moving said rollcarrying structure axially to and fro with respect to the metal tube, said rolls being constructed and arranged to subject the metal tube to cold rolling to reduce its diameter while said roll-carrying structure is moving in one direction during its to and fro movement, means for continuously rotating said roll-carrying structure about the axis of the metal tube during its to and fro movement and while said roll-carrying structure is moving in said one direction and the metal tube is being subjected to the aforesaid cold rolling, said means for 219.23482 1 axially-moving. said roll-carryingstructure ineluding a n r ReferenesrCited in the 51e of this Apatent driving member, means 'for imparting a reciprocating NIT fl to and fro movement to said driving member, a member U ED STATES PATENTS onnectngfsaid driving member and said roll-carrying 4901628 Heckelt y 12111.v 24, 1.3 93 structure, and means including a hollow part for journal 5 1,219,802 Brightman 1 M312 20, 1917 ing said rotatable roll-carrying structure, said member 2,192,808 V311 d@ Bullglaal' M211 5 1941) ,extending through said hollow part. 2,387,515 InSlee Oct. 23,' 1945 6. Arolling mill as set forth in claim 5in which said 2,503,464 Bannister a Apr. 11, 1950 member connecting said `driving member and said roll- 2,560,934 'Coe July 17, 19451 carrying structure comprisesva double-walled hollow tube 10 y 2,713,501 51,11%@ July 25| 1955 `to form a passage for conducting a cooling liquid theref Ithrmrghrto said roll-carrying structure. 

